Voltage clamps sometimes limit changes that occur in circuit performance caused by changes in one or more variables such as process, voltage, temperature (PVT) variations, resistance, logic, and the like. Some circuits require a minimum virtual voltage to effectively operate. Some voltage clamps include diode-connected p-metal oxide semiconductor (PMOS) transistors that clamp the virtual voltage of a circuit to reduce the effects various process variables have on the virtual voltage, and ultimately, the circuit performance.